Added base test result parser class. Implemented Go test result parser based on Go's built in test utility output.

Test Plan: Ran PhpunitTestEngine unit test and used both test result parsers to generate test results.

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, Korvin, aurelijus

Differential Revision: https://secure.phabricator.com/D4676